Graphic films are used, for example, to apply designs, e.g. images, graphics, text and/or information, on windows, buildings, pavements or vehicles such as autos, vans, buses, trucks, streetcars and the like for e.g. advertising or decorative purposes. Many of the surfaces, e.g. vehicles, are irregular and/or uneven.
For graphic films, it is desirable to have a film that accommodates curves, depressions or projections on a substrate surface so that the film may be stretched around curves or projections, or may be pressed down into depressions without breaking or delaminating the film. This characteristic is generally referred to as conformability. It is also desirable that the film does not delaminate or release from the substrate surface after application (known as popping-up). Graphic films may also be imageable (i.e. able to receive printing and/or graphics) and exhibit good weathering for outdoor applications.
Polyvinyl chloride (PVC) films are conventionally used for a wide of variety of applications including graphic films. PVC has many properties that are advantageous for such applications and are easily printed using current printing technologies, e.g. piezo ink jet. For example, PVC graphic films are conformable to the varying topographies present on the exterior of a substrate, e.g. a vehicle. However, in some cases the application of halogen-containing plastics may be undesirable for environmental reasons.
Polyolefin films and their corresponding use as graphic films are advantageous in that they typically do not contain halogens. However, polyolefin films are difficult to image and thus may require the application of an additional image receptive layer, such as an ink receptive layer, toner receptive layer, primer layer or the like.